1. Field of the Invention
The present invention relates to magnetic recording media, a method of recording a servo pattern on magnetic recording media, and a magnetic head for recording a servo pattern on magnetic recording media, and more particularly, to a magnetic recording medium appropriate for recording thereon a servo pattern when a position where user data is recorded is patterned, a method of recording a servo pattern on the magnetic recording medium, and a magnetic head appropriate for recording a servo pattern on the magnetic recording medium.
2. Description of the Related Art
Recently, information memory devices for recording/reproducing high-density information are required due to the rapid increase in the amount of information to be processed. In particular, hard disk drives using magnetic recording media have characteristics such as large storage capacity and fast access time. Accordingly, the hard disk drives have been highlighted as information memory devices for various digital devices as well as computers.
However, in the case of magnetic recording media having a continuous magnetic recording layer (hereinafter, referred to as continuous media), when the size of a bit that is the minimum recording unit of data or the pitch width of a data track is reduced to a certain limit, noise increases and the recording stability is rapidly degraded due to the effect of a neighboring area. Thus, there is a limit in increasing the recording density by increasing a linear recording density or a BPI (bits per inch), that is, a density in a disk rotational direction, or a track density or a TPI (tracks per inch), that is, a density in a disk radial direction.
Discrete track media and patterned media on which the position for magnetic recording is patterned in advance in the manufacturing step have been studied in order to incease the recording density. The discrete track media have a structure in which a gap between data tracks is empty or filled with a non-magnetic material. Also, the patterned media have a structure in which a bit, that is, the minimum recording unit, is patterned in a shape of an island and the outside of the island is empty or filled with a non-magnetic material. However, it is difficult to apply a servo method and system, which are used for continuous media, to discrete track media and patterned media.
One of the servo methods used for continuous media is the sector servo method. In the sector servo method, a magnetic recording medium includes a data area and a servo area for each sector, and servo information to allow a magnetic head to be correctly located at a desired position on the magnetic recording medium is recorded in the servo areas. In particular, a servo pattern is formed in the servo areas so that the magnetic head can correctly follow a data track on the magnetic recording medium. In the case of continuous media, the servo pattern includes a burst that is partially deviated from a regular position on the data track. However, in the case of discrete track media or patterned media, since the position for magnetic recording is patterned in advance in the manufacturing step, the magnetic recording is not performed in an area other than a preset position. Thus, since the burst pattern is not formed at a position partially deviated from a track, it is difficult to apply the servo pattern used for the continuous media to the discrete track media and patterned media.
Furthermore, for the continuous media, the servo pattern that is first written provides a reference position of a data track when data is recorded and allows the detection of a degree of deviation of the magnetic head from the data track when the data is reproduced. However, since in the discrete track media and patterned media the data track is determined in advance in the manufacturing step, it is difficult to apply the servo method used to the continuous media.